The present invention relates to the liquid supply assemblies for gravity fed liquid (e.g., paint) spraying devices or spray guns.
Various liquid supply assemblies have been described for use with gravity fed liquid (e.g., paint) spraying devices or spray guns, including those described in the international application published as International Publication Number WO 98/32539 on Jul. 30, 1998, the content whereof is incorporated herein by reference. The supply assembly including a collapsible liner that is described and claimed in that application should provide advantages over the prior art liquid supply assembly also described in that application.
The present invention provides a liquid supply assembly for use with gravity fed liquid spraying devices that, like the liquid supply assembly described and claimed in WO 98/32539, should also provide advantages over the prior art liquid supply assembly described in that application.
According to the present invention there is provided a liquid supply assembly adapted for use on a gravity fed liquid spraying device that comprises (1) a mixing cup of stiff polymeric material that bears indicia on its side wall indicating the levels to which a plurality of different liquids should be sequentially poured into the cup to achieve a predetermined ratio between the liquids; (2) a first adapter comprising a central portion having a through opening and a transverse portion including a peripheral part defining a groove along its inner surface adapted for sealing engagement with a top end of the mixing cup; (3) a second adapter having a through opening, a first end portion adapted to releasably engage the inlet port of the spraying device; and a second end portion having a connector part adapted for releasable liquid tight engagement with a connector part on the central portion of the first adapter with the through openings in communication.
The mixing cup is of a known type commonly used in paint shops to mix different paints and/or to mix paint with solvent. Those liquids are mixed using indicia on the side walls of the mixing cup. That indicia indicates the levels to which two or three different liquids should be sequentially poured into the mixing cup to provide a predetermined ratio between those liquids, such indicia being provided for a plurality of different ratios. Prior to this invention, liquid from the mixing cup was poured into a liquid supply assembly for a spray gun, and if liquid remained after the spraying operation was complete, that remaining liquid was sometimes poured back into the mixing cup, an air tight cover was applied thereto, and the liquid (e.g., paint) was stored for future use in the covered mixing cup.
The present invention affords further use of that mixing cup as part of the liquid supply assembly for the spraying device. This eliminates the need to pour the mixed liquid (e.g., paint) out of the mixing cup prior to spraying, or to pour unsprayed liquid back into the mixing cup after the spraying operation. Instead, the liquid is mixed in the mixing cup, remains in the mixing cup during the spraying operation when the mixing cup becomes part of the liquid supply assembly for the spraying device, and if unsprayed liquid remains after the spraying operation, it can be retained in the mixing cup which is then separated from the rest of the liquid supply assembly and can have a conventional air tight cover applied to it for storage.
A vacuum relief for the liquid supply assembly can be provided by inserting a tapered removable pin (e.g., a pin of the type sometimes called a xe2x80x9cpush pinxe2x80x9d) through the side wall of the mixing cup adjacent its bottom wall. That pin is removed during use of the mixing cup in the liquid supply assembly for the spraying device when the mixing cup is positioned with its bottom wall uppermost so that air can enter the cup through an air passageway formed by the pin above the liquid being supplied to the spraying device. Before and after the spraying operation when the cup is supported on its bottom wall that pin may be positioned in the passageway it forms to preclude liquid leaking out of the mixing cup through that passageway.
The liquid supply assembly can also include a removable filter assembly for filtering liquid leaving the mixing cup during the spraying operation.